This is a longitudinal study of three different populations in Oklahoma; family members of known homozygous alpha1 antitrypsin deficient subjects; all adult admissions to the Medical and Surgical services of a University Hospital; and some 1,000 normal inhibitants of a rural county representing a pre-identified and representative sampling of that community. The development and progression of chronic bronchitis emphysema in these three groups will be followed by annual examinations and recording of various clinical, physiological, and biochemical parameters. From these observations it is hoped to clearly establish the relationship between heterozygous alpha1 antitrypsin deficiency and chronic bronchitis-emphysema. Other key factors in the development of this disease will also be identified in this population, which is composed of almost equal groups of Indians, Blacks and White subjects.